If you want to level up your Sims' Ballet skill quickly, use the Ballet Barre over and over again, as it has more skill points than the record player.

The pipes upstairs are part of a mini-game for woodworkers. If they build a small Sim-like robot, it will try to escape, so you must guide it over the pipes to reach your Sim at one of the windows. Your Sim will catch the robot and it will be part of the Woodworking collection.

There is also toilets to raise your Sim's bladder and chairs for Sims to sit at.